Ski boots are generally provided with a rapid attachment device of the toggle type, comprising on the one hand, a rack with several notches attached to one of the elements to be tightened, and on the other hand a tightening lever connected, through a traction element, to the other element to be tightened. At one of its ends, the lever carries a hooking finger to be lodged in one of the notches of the rack, depending on the desired degree of tightening. Such a device enables the tension of the tightening element to be varied, i.e., the level of tension can be altered at the user's discretion.
It is known, e.g., from French Patent No. 1,538,725, to provide means enabling continuous adjustment of the tension of a traction element on ski boots. Such means normally comprise a screw-nut assembly interposed between a hooking buckle and the traction element, the buckle being engaged with one of the notches of a rack provided on the tightening lever. However, such a device has the drawback that all of its constituent elements are visible, thus detracting from the appearance of the assembly, and their operation can be altered as a result of the penetration of snow or other foreign bodies.